Field of the Invention
The present invention relates to a liquid ejection substrate, a liquid ejection head, and a liquid ejection apparatus used to eject various liquids including ink.
Description of the Related Art
For example, in an inkjet printing head capable of selectively ejecting ink from a plurality of ejection openings, the ejection openings need to be densely arranged to print a high-quality image with high accuracy. Further, since the ink is thickened due to the evaporation of moisture in the ink from the ejection openings, there is a need to provide a countermeasure for an influence on a high-quality printing operation.
In order to handle such a demand Japanese Patent No. 4722826 discloses a method of circulating ink through a pressure chamber so that ink thickened inside the pressure chamber communicating with an ejection opening does not stay therein. Japanese Patent No. 4722826 discloses a configuration in which a member having a curved ink passage is formed by extruding aluminum and the ink is caused to forcedly flow into the pressure chamber corresponding to each of the plurality of ejection openings though the ink passage formed inside the member. Japanese Patent No. 5264000 discloses a configuration in which a member having a three-dimensionally curved ink passage is formed and the ink is caused to forcedly flow into the pressure chamber corresponding to each of the plurality of ejection openings through the ink passage formed inside the member.
However, in Japanese Patent No. 4722826 and Japanese Patent No. 5264000, the ink passage has a complex shape and thus a plurality of the ink passages cannot be easily and densely arranged so that the ink is circulated through the pressure chamber corresponding to each of the plurality of ejection openings densely arranged.